| Mary W. Chapin | |
| Order: | 3rd |
| President of Mount Holyoke College (Acting Principal and Principal) | |
| Term Start: | 1850 |
| Term End: | 1865 |
| Predecessor: | Mary C. Whitman |
| Successor: | Sophia D. Stoddard |
| Birth Date: | 1820 |
| Alma Mater: | Mount Holyoke College (Mount Holyoke Female Seminary) |
| Profession: | Professor |
Mary W. Chapin (1820–1889) was an American educator who served as the third president (referred to at that time as "acting principal" and "principal"[1]) of Mount Holyoke College (then Mount Holyoke Female Seminary) from 1850 to 1852 and Principal from 1852 to 1865. She graduated from Mount Holyoke in 1841 and taught there for seven years before becoming Head.